// Wayland协议服务实现 - 仅使用safe Rust

#![forbid(unsafe_code)]

use std::sync::Arc;
use std::sync::Mutex;
use std::collections::HashMap;
use log::{info, warn, error};
use std::net::{UnixListener, UnixStream};
use std::io::{Read, Write};
use std::thread;
use std::sync::mpsc;

// 导入能力类型和错误类型
use super::{Capability, CapabilityId};
use super::gfx_service::{GraphicsService, DisplayModeInfo, GraphicsError};

// Wayland连接ID
pub type WaylandConnectionId = u64;

// Wayland协议错误
#[derive(Debug, Clone, PartialEq)]
pub enum WaylandError {
    ConnectionFailed,
    ProtocolError,
    GraphicsError(GraphicsError),
    InvalidConnection,
    ResourceError,
}

// Wayland资源ID
pub type WaylandResourceId = u32;

// Wayland消息类型
#[derive(Debug, Clone, Copy, PartialEq)]
pub enum WaylandMessageType {
    CreateSurface = 1,
    CommitSurface = 2,
    CreateBuffer = 3,
    AttachBuffer = 4,
    Configure = 5,
    Ping = 6,
    Pong = 7,
}

// Wayland消息
pub struct WaylandMessage {
    pub msg_type: WaylandMessageType,
    pub sender_id: WaylandResourceId,
    pub target_id: WaylandResourceId,
    pub args: Vec<u8>,
}

// Wayland连接
pub struct WaylandConnection {
    id: WaylandConnectionId,
    stream: UnixStream,
    resources: HashMap<WaylandResourceId, WaylandResource>,
    next_id: WaylandResourceId,
}

// Wayland资源
pub enum WaylandResource {
    Surface {
        width: u32,
        height: u32,
        buffer_id: Option<WaylandResourceId>,
    },
    Buffer {
        gpu_buffer_id: u64,
        width: u32,
        height: u32,
        format: u32,
    },
    Display,
    Registry,
}

// Wayland服务
pub struct WaylandService {
    graphics_service: Arc<Mutex<GraphicsService>>,
    connections: HashMap<WaylandConnectionId, Arc<Mutex<WaylandConnection>>>,
    next_connection_id: WaylandConnectionId,
    listener: Option<UnixListener>,
    running: bool,
    mem_cap: Capability,
}

impl WaylandService {
    // 创建新的Wayland服务
    pub fn new(graphics_service: Arc<Mutex<GraphicsService>>, mem_cap: Capability) -> Result<Self, String> {
        Ok(WaylandService {
            graphics_service,
            connections: HashMap::new(),
            next_connection_id: 1,
            listener: None,
            running: false,
            mem_cap,
        })
    }

    // 启动Wayland服务
    pub fn start(&mut self) -> Result<(), String> {
        if self.running {
            return Ok(());
        }

        // 创建Unix socket监听
        let listener = UnixListener::bind("/tmp/wayland-0").map_err(|e| {
            format!("Failed to create Wayland socket: {}", e)
        })?;
        self.listener = Some(listener);
        self.running = true;

        info!("Wayland service started successfully");

        // 启动连接处理线程
        let listener = self.listener.as_ref().unwrap().try_clone().map_err(|e| {
            format!("Failed to clone listener: {}", e)
        })?;
        let (tx, rx) = mpsc::channel();

        let _handle = thread::spawn(move || {
            for stream in listener.incoming() {
                match stream {
                    Ok(stream) => {
                        tx.send(Ok(stream)).unwrap();
                    }
                    Err(err) => {
                        tx.send(Err(format!("Incoming connection error: {}", err))).unwrap();
                    }
                }
            }
        });

        // 处理新连接的线程
        let connections_arc = Arc::new(Mutex::new(self.connections.clone()));
        let next_id = self.next_connection_id;
        let graphics_service_clone = Arc::clone(&self.graphics_service);
        let mem_cap_clone = self.mem_cap.clone();

        let _handle = thread::spawn(move || {
            let mut next_conn_id = next_id;
            while let Ok(result) = rx.recv() {
                match result {
                    Ok(stream) => {
                        let connection_id = next_conn_id;
                        next_conn_id += 1;

                        let connection = Arc::new(Mutex::new(WaylandConnection {
                            id: connection_id,
                            stream: stream.try_clone().unwrap(),
                            resources: HashMap::new(),
                            next_id: 1,
                        }));

                        // 添加初始资源
                        {
                            let mut conn = connection.lock().unwrap();
                            // 添加显示资源
                            conn.resources.insert(1, WaylandResource::Display);
                            // 添加注册表资源
                            conn.resources.insert(2, WaylandResource::Registry);
                            conn.next_id = 3;
                        }

                        // 存储连接
                        connections_arc.lock().unwrap().insert(connection_id, Arc::clone(&connection));

                        // 为每个连接启动处理线程
                        let conn_clone = Arc::clone(&connection);
                        let graphics_clone = Arc::clone(&graphics_service_clone);
                        let mem_cap = mem_cap_clone.clone();

                        thread::spawn(move || {
                            WaylandService::handle_connection(conn_clone, graphics_clone, mem_cap);
                        });
                    }
                    Err(err) => {
                        error!("{}", err);
                    }
                }
            }
        });

        Ok(())
    }

    // 处理Wayland连接
    fn handle_connection(
        connection: Arc<Mutex<WaylandConnection>>,
        _graphics_service: Arc<Mutex<GraphicsService>>,
        _mem_cap: Capability
    ) {
        let connection_id = connection.lock().unwrap().id;
        info!("Wayland connection established: {}", connection_id);

        // 这里实现Wayland协议的具体处理逻辑
        // 包括消息解析、资源管理、事件处理等
        // 为了简化，这里只实现了基本框架

        // TODO: 实现完整的Wayland协议处理

        // 发送初始化消息
        WaylandService::send_connection_init(&connection);

        // 简单的消息循环（仅用于示例）
        let running = true;
        while running {
            // TODO: 实现实际的消息读取和处理
            thread::sleep(std::time::Duration::from_millis(10));
        }

        info!("Wayland connection closed: {}", connection_id);
    }

    // 发送连接初始化消息
    fn send_connection_init(_connection: &Arc<Mutex<WaylandConnection>>) {
        // 这里应该发送Wayland协议的初始化消息
        // 包括display、registry等基本对象的创建
        // 为了简化，这里省略了具体实现
    }

    // 解析Wayland消息
    fn parse_wayland_message(_data: &[u8]) -> Option<WaylandMessage> {
        // 这里实现Wayland消息的解析逻辑
        // 为了简化，这里返回None
        None
    }

    // 处理Wayland消息
    fn handle_wayland_message(
        connection: &mut WaylandConnection,
        message: &WaylandMessage,
        graphics_service: &mut GraphicsService,
    ) -> Result<(), WaylandError> {
        // 根据消息类型处理不同的请求
        match message.msg_type {
            WaylandMessageType::CreateSurface => {
                // 创建surface
                let surface_id = connection.next_id;
                connection.next_id += 1;
                
                connection.resources.insert(surface_id, WaylandResource::Surface {
                    width: 0,
                    height: 0,
                    buffer_id: None,
                });
                
                // 发送创建surface的响应
                // TODO: 实现响应逻辑
                
                Ok(())
            },
            WaylandMessageType::CreateBuffer => {
                // 创建buffer
                // 解析参数：width, height, format
                // 为了简化，这里假设参数正确解析
                let width = 800;
                let height = 600;
                let format = 0; // RGBA8888
                
                // 通过图形服务创建GPU缓冲区
                let gpu_buffer_id = graphics_service.create_buffer(width * height * 4, 0)?;
                
                // 创建Wayland缓冲区资源
                let buffer_id = connection.next_id;
                connection.next_id += 1;
                
                connection.resources.insert(buffer_id, WaylandResource::Buffer {
                    gpu_buffer_id,
                    width,
                    height,
                    format,
                });
                
                // 发送创建buffer的响应
                // TODO: 实现响应逻辑
                
                Ok(())
            },
            WaylandMessageType::CommitSurface => {
                // 提交surface
                if let Some(WaylandResource::Surface { width, height, buffer_id }) = 
                    connection.resources.get(&message.target_id)
                {
                    if let Some(buffer_id) = buffer_id {
                        if let Some(WaylandResource::Buffer { gpu_buffer_id, .. }) = 
                            connection.resources.get(buffer_id)
                        {
                            // 通过图形服务提交缓冲区到显示设备
                            graphics_service.present_buffer(0, *gpu_buffer_id)?;
                        }
                    }
                }
                
                Ok(())
            },
            _ => {
                // 处理其他消息类型
                Ok(())
            }
        }
    }

    // 停止Wayland服务
    pub fn stop(&mut self) -> Result<(), String> {
        if !self.running {
            return Ok(());
        }

        self.running = false;
        
        // 关闭监听器
        if let Some(listener) = self.listener.take() {
            drop(listener);
        }
        
        // 关闭所有连接
        self.connections.clear();
        
        info!("Wayland service stopped successfully");
        
        Ok(())
    }
}

impl Drop for WaylandService {
    fn drop(&mut self) {
        if self.running {
            let _ = self.stop();
        }
    }
}